Seattle-based Cray is behind the new world's fastest supercomputer, according to a list released Monday.

"Titan," a Cray XK7 system activated last month at Oak Ridge National Laboratory, in Tennessee, took the top spot in the 40th edition of the twice-a-year TOP500 List. Titan achieved 17.59 Petaflops (quadrillions of calculations per second), topping Lawrence Livermore (Calif.) National Laboratory's IBM-based Sequoia system, which hit 16.32 Petaflops.

"The new Top500 list clearly demonstrates the U.S. commitment to applying high-performance computing to breakthrough science, and that's our focus at Oak Ridge," laboratory Director Thom Mason said in a news release. "We'll deliver science from Day One with Titan, and I look forward to the advancements the Titan team will make in areas such as materials research, nuclear energy, combustion and climate science."

Titan replaced Oak Ridge's XT5 Jaguar computer, which was the world's fastest in November 2009 and June 2010. It is capable of a theoretical peak speed of 27 Petaflops, 10 times faster than Jaguar, while using approximately 9 megawatts of electricity, roughly the amount required for 9,000 homes and just 20 percent more than Jaguar, according to the laboratory.

The energy savings come from a hybrid architecture that combines traditional central processing units with graphic processing units, which were first created for gaming.

"It's not practical or affordable to continue increasing supercomputing capacity with traditional CPU-only architecture," Jeff Nichols, the laboratory's associate director for computing and computational sciences, said in the release. "Combining GPUs and CPUs is a responsible move toward lowering our carbon footprint, and Titan will enable scientific leadership by providing unprecedented computing power for research in energy, climate change, materials, and other disciplines."

So what's the point of all that speed?

It "will allow U.S. scientists and industry to address problems they could only dream of tackling before," said Buddy Bland, Titan project manager at the U.S. Department of Energy's Oak Ridge Leadership Computing Facility.

Early applications include researching the magnetic properties of materials to accelerate such technologies as next-generation electric motors and generators; improving fuel efficiency by modeling combustion of large-molecule hydrocarbon fuels; faster fuel-rod simulations that extend the life cycles of aging nuclear reactors and ensure they remain safe; and calculating specific climate change adaptation and mitigation scenarios.